Another long time lurker here (I am not a professional pilot).
About the video (again): as others have already said, it is not necessary to have 10,000 followers to go live on Facebook. , that limit is for the in-stream advert program. What is technologically possible is exactly what is stated in the media: the passenger was streaming live to his facebook page which was restricted, but others who had access to it subsequently shared it.
The other point made is that there is a difference in the time gap between the wing drop and the crash in the external and internal videos. I went back and looked at this. In the external video, the difference is approximately 5.5 seconds. In the internal video, it is about 3 seconds. These are approximate times as there is no one very clear moment of roll or crash in the internal video. If we take into account that sound travels about a kilometre in three seconds, the times seem about right.
This is a Rumour Network and always seems to me like a healthy outlet for relatively respectful speculation, but I was under the impression that Aviation Herald was taken to be somewhat of an online paper-of-record for the industry, but it seems like it is just run by one person and is still very confidently stating with certainty that this video is fake (and calling it "dilettantish"). Maybe the video will turn out to be fake (I doubt it), but anyway, with the current evidence such a certain statement makes the site look bad.
On the crash - the comment by B0OM is helpful. One question I would add: given how common you say the situation is, is there a risk of alarm fatigue with the stick shaker? How often in a pilot's career might they have the shaker activate? And what does the stall recovery procedure say to do with the flaps?